On 04/10/2020 04:35, The Natural Philosopher wrote:

Now I have three shaggy inkcaps in an isolated piece of lawn that has
never ever had any fungi before. No, I don't understand it, either.
But butter bacon fat and garlic are waiting for them when they are old
enough and big enough...

Edible provided you don't drink alcohol at the same time. They contain
that basis of anatabuse which can make it unpleasant if you do.

This time of year all the fungi respond the the first frosts with
fruiting bodies and annoyingly the ones in my lawn are yellow stainers
rather than proper edible mushrooms. I have plenty of other species but
none of them are remote edible or apetising to look at.

I think you get fungus if the bark gets damaged in any way, and once
there, if its the right sort it just kills everything by tapping into
the sap bearing channels. So roots survive, but anything above the
fungus does not.

I can't think of fungi specific to viburnums but based on the most
common cause of trouble in waterlogged ground phytophthora seems plausible.

https://www.rhs.org.uk/Advice/profile?pid=542

If the root is healthy it might be worth leaving it to produce new shoots.

OTOH it may be the roots where it originated.
A search on the RHS plant disease page might yield something.



--
Regards,
Martin Brown